Air Pump affect MPGs?

[Cory]

This is only one question of a couple I have...

I bought the bjs exhaust kit, went to install it, and sheared a few bolts off in the manifold off the y-pipe. So while I decide if I want to pull those out, or just toss another used set of manifolds on, I had a few other questions...

to weld, or to clamp exhaust pipe? the previous owner had everything welded. Who ever did the welding did a shoddy job, because the welds ended up being very holey (and not just on sundays). So one would think that by clamping everything, you don't have to worry about the weld joint being the weakest link in the exhaust system.

Next question- to air pump or not to air pump... reading a few threads on here, it would seem if you don't need it, don't use it. But since I got the kit with the cat with an air tube, I should use the air pump, to avoid early deterioration of the cat.

But running the air pump "technically" can affect gas mileage, because it's an add'l accessory being run, correct?

the easy solution would be just to convert everything to clamp, run the air pump till it or the exhaust dies, and just redo it all, with a 3way cat and no air pump...

or is there a simpler solution to something I'm probably making more complicated than it already is?

Either way, now I gotta find a new ypipe, for the exhaust kit I have taking up space on my harley and the garage floor...

[bigun]

I replaced mine on my 91 Dodge and lost 4 MPG.

[tgreese]

It is a very small parasitic load, so yes, it does decrease mileage slightly. But on or off, I predict the effect will be negligible, basically unmeasurable.

IMO their main downside is that they are a maintenance headache. The tubes will rust out and the pump will rust solid if it's not used. If you remove the pump and leave the tubes in place, they will rust out. But if it works, I would definitely keep it. Your truck is new enough that there are jurisdictions where you have to have all the smog equipment, and the truck will be worth more if it all functions.

[will e]

Above advice is good. No real milage difference and some states would check for it. If I was shopping for a replacment waggy a missing pump would be a negative

[FSJ Guy]

Above advice is good. No real milage difference and some states would check for it. If I was shopping for a replacment waggy a missing pump would be a negative

X2.

You can buy a replacement pump, but it does NOT come with the pulley. You NEED the pulley (of course) to use the pump.

[Carnuck]

I took mine off and went with a high flow cat. The exhaust emission levels dropped and it had more power.

[joe]

If you see any mpg improvements it'll be on the east side of the decimal point and not on the west side where it matters. My vehicles usually sit for extended periods and the pumps will freeze up from lack of use so I usually remove them before they go south. Never noticeably improved my mpgs.

[Carnuck]

When they are just prior to seizing up, they suck fuel and power from the motor.

[Rich88]

It is a very small parasitic load, so yes, it does decrease mileage slightly. But on or off, I predict the effect will be negligible, basically unmeasurable.

X2. I've run with it on and off. Any claims of meaningful decrease in power or mpg is an exaggeration.

[Carnuck]

Unless it's seizing up.

[FSJ Guy]

Unless it's seizing up.

Which only lasts for about 5 minutes because then the belt heats up and breaks. LOL!

[Cory]

thanks guys. I guess I'll roll with the air pump till it dies!

[will e]

i picked one up at autozone. When it dies they replace it free.

[Carnuck]

Which only lasts for about 5 minutes because then the belt heats up and breaks. LOL!

Mine went on for several weeks and I was concerned about the loss of power, but I had to go to work 16 hours a day. It finally seized while driving on the Trans Canada and nearly stalled the motor before the belt broke and then all the power was back in a flash!

[serehill]

Really My 2 pennies.

If you don't have to run it don't. While your doing all this stuff get rid of several problems the entire system is how old? The difference like everyone said is not worth worrying about. The issue is the old parts will just cause more issues later. Why keep on dealing with something or wait until it locks up that you'll eventually eliminate. If you do it now trust me something else will take up your time later.
Just my opinion. I took all mine off & am real happy I have not had to deal with it again. There's always plenty of other stuff to do.